Switch apparatus



5 Sheets-Sheet 1. i

M. 'M. DAVIS. SWITCH APPARATUS.

No. 426,583. Patented Apr. 29, I890.

(No Model.) 7 5 Sheets-Sheet 2.

M. M. DAVIS. SWITCH APPARATUS.

Patented Apr. 29, 1890.

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(No Model.) 5 Sheets-Sheet 3.

M. M. DAVIS.

SWITCH APPARATUS.

No. 426,583. Patented Apr. 29, 1890.

(No Model.) 5 Sheets-Sheet 4.

M. M. DAVIS. SWITGH APPARATUS.

No. 426,583. Patented Apr. 29, 1890-.

5 ShetsSheet 5.

(No Model.)

M. M. DAVIS. SWITCH APPARATUS.

No. 426,583. Patented Apr. 29, 1890.

5 aging or troublesome changes in the flow of UNITED STATES PATENT OFFICE.

MINOR M. DAVIS, OF BROOKLYN, NEW YORK.

SWITCH APPARATU S.

SPECIFICATION forming part of Letters Patent No. 426,583, dated A ril 29, 1890.

Application filed June 11, 1889. Serial No. 313,827. (No model.)

To all whom it may concern.-

Be it known that I, MINOR M. DAvIs, a citiprimarily, for use at a main telegraph-office [-.O

in which-local circuit and branch lines are supplied from dynamo-machines.

In the use of the apparatus at a telegraphoffice it frequentlybecomes necessary to connect various local circuit-s, as in the case of duplex or quadruplex locals, in order that a message may be repeated from one line to another, or to connect a branch or office line to a local circuit in such way that the leg or loop leading tothe branch office shall become in effect an extension of the sending or receiving local of a duplex or quadruplex set. In the absence of any special provision these various changes would obviously be accompanied by changes in the resistance in circuit with the dynamo, and consequently damcurrent in the circuit for which it is necessary to make some compensation or adjustment. Thus, for instance, the introduction of abranch-oftice loop or wire would increase the total resistance and perhaps cut down the current below the working margin; or if the current flows in proper amount when the branch wire is in circuit with the local sendin g or receiving circuit the withdrawal of the branch wire would so reduce the resistance shunted or cut out of or into circuit by the spring-jack wedge when the latter is inserted into or withdrawn from the spring-jack.

My invention consists further in a certain novel form of spring-jack involving the use of a double contact-jaw, or jaw made in two pieces insulated from one another, but adapted to be connected by the live or conducting side of a Wedge when the latter is inserted into the spring-jack. My invention consists, also, in certain improved combinations of switches and springjacks, whereby the various connections'may be made, and whereby, among other things, a branch wire or loop may be connected into a local formed of two locals connected for repeating, and the equalizing-resistances may at the same time be properly manipulated to keep the strength of the current uniform.

In the accompanying drawings, Figure 1 is a general diagram of apparatus and circuits embodying my invention. Figs. 2, 3, 4, 5, and 6 are diagrams illustrating various conditions of the same in use.

0 indicates the movable jaws of a number of spring-jacks, and a 1) two opposite contact jaws or plates of each jack, which plates are separated or insulated from one another, as shown, but are connected to the terminals of an artificial resistance R, preferably adjustable, and forming the equalizing or compensating resistance. bears 011 plate a. The supplemental plateb is adapted to be engaged by the spring-jack wedge when inserted with the jack andto The movable jaw C normally make contact with a conducting side thereof pleted through the resistances R and the spring-jack jaws O to earth or return-circuit. A B indicate, respectively, the local-circuit apparatus of two sets of duplex or quadruplex apparatus. In the case of a quadruplex telegraph they may be either the No. 1 side or the No. 2 side. The transmitter indicated is, however, the transmitter for the No. 2 side working by changes of tension. Main lines and other parts are omitted for the sake of simplicity.

In the set A the sounder in the receivinglocal is indicated at S and the relay through from the dynamo and connected to the sup plemental jack, its circuit then being through such jack, resistance, and ground when no wedge is in place. By means of a suitable switch in the local circuit, which switch may be the lever of H, working in connection with a stud in the switch-board connected to earth atea'ch local of set B .may be connected directly to earth.

KK? indicate a pair of springq'ack wedges connected by a suitable flexible cord, and each having a live or conducting side and a dead or insulated side. The live :side of K is short and adapted to bear on plate CL of the spring-jack, being out of contact with b when it is inserted. The live side of K is longer and adapted to bear on both a and b, so as to connect them directly and shunt'resistance R.

L L is another pairof wedges connected electrically by a flexible cord and each like wedge K M is a wedge like K connected to a branch wire or leg 11, leading to the receiving side of branch office E, at which it is desired to receive a message received at the main office on one of the sets of duplex 0r quadruplex telegraph apparatus, while M is a similar wedge connected to the wire 10, leading to the sending side of the branch office.

M is a wedge having both sides formed of conducting material for use with a loop or metallic circuit 12, formed through the sending or receiving apparatus of a branch office F.

It will be understood that the resistance B should be approximately equal to the resist ance'ofthebranch or local which is to be placed in circuit with the local to which said resistance R is normally connected. Adjustments ofsuch resistance may be made by the ordinary means; or minor adjustments of resistance may be made, when necessary, by resistance-plu'gs such as indicated at M, and consisting of a coil of fine wire on a handle terminating in two plates insulated from one another'like M and adapted to be inserted into aspring-jack in contact with a conquer. I

Simiing side of a wedge already inserted or separately.

Fig. 2 shows the condition when the sending side ofthe branch office is in circuit with the sending-local of a duplex or quadruplex set. The resistance R, approximately equal to the resistance in the sending side of the branch-office leg, is shunted, and the current is the same as when the local circuit is completed at the main office through the springjack.

Fig. 3 shows the receiving side of thebranch 'office similarly connected to and forming an extension of the receiving local for a du plex or quadruplex set. It is obvious that a loop could be connected to the local by a wedge M and that the equalizingmesistance R would be shunted in the same way and be automatically restored to the local circuit on withdrawal of the wedge. The only difference in the circuits would be that the circuit, instead of going to ground at the branch office, would return by one side of the loop' and go to ground spring-jack.

Fig. 4 shows the two sets connected by wedges K K for repeating from one set to the other. The locals of one set, as B, are disconnected from the dynamo by the switches between the local-circuit apparatus and dynamo, and the side so disconnected is connected directly to earth or return-wire. The

through the jaw C of the connected locals arefed through the dynamoconnections of the other set. On tracing the circuits shown it will be found that the receiving-local of set A finds circuit through its resistance R, which is not cut out by K, through the sending-local of set B, and by switch II directly to earth or return-wire and back to the dynamo. The resistance R at set B is cut out by wedge K In a similar way the circuit of the sending-local of set A finds circuit through the receiving-local of set B and to ground through the grounding or disconnecting switch of each receiving-local.

On disconnecting the sets the switches of set B are turned to connect the locals directly tothe dynamo. In each case it will be seen that one of the equaliz inga'esistances only is IIO retained in circuit, the other being removed,

so as to leave the resistance of the connected locals substantially the same as each ofthem when disconnected from one another. There is of course the added resistance of the instruments themselves and connecting-wire on one local; but the artificial resistances R are made large as compared with these. The difference of total resistance need not be sufficiently large to produce any harmful eii'ect.

The locals might be connected by the wedges L L as shown in Fig, 5, and these arepreferably'ernployed when it is desired. to .leave the sets in condition forconnection of a branch wire to the connected locals, so as to form an extension of the local after the manner shown in Fig. 6.

In Fig. the local of one set, as B, is conthrough the resistance connected to the ground by means of the shifting switch H in the local circuit to the dynamo. The sending and receiving local of one set may be both connected to the locals (receiving or'sending) of the other in the same way. As both wedges L L here act to cut out equalizing-resistances, and as spring-jack C retains its resistance R in circuit, the practical result is the same as in the case of Fig. 4., but with the addition that, as shown in Fig. 6, the branch circuit may be made an extension of each connected pair of locals by simply inserting a wedge M or M into 0 so as to cut out'resistance R connected therewith in the same manner as was done'with the resistance of O in the case of Figs. 2 and 3.

The purpose of connecting in the manner shown in Fi 6 is to permit the branch office to also receive the message received in the set E and repeated by set A.

While I have described my invention as applied to telegraph apparatus, I do not limit myself in this respect, since it is obvious that the same combinations of circuits and devices might be used in connection with other apparatus.

That I claim as my invention is- 1. In an electrical switch apparatus, the combination, with a spring-jack having one of its contact-jaws subdivided, and a branch or circuit connecting the divisions of the contact, of a wedge having a live side adapted to bear on both subdivisions simultaneously, and an appendant circuit, substantially as shown, for the purpose of replacing the former circuit with the latter.

2. The combination, in a spring-jack, of a contact a, a jaw normally bearing on the same, a second cont-act I), connected with the first through a separate conductor, and a springjack wedge, as and for the purpose described.

3. The combination, with telegraph local and branch circuits supplied from dynamos, of spring-jacks in the several circuits, equalizing-resistances in the permanent springjack connections, and spring-jack wedges for shunting or cutting out said resistances.

4:. The combination, with telegraph local and branch circuits, of spring-jacks in said circuits, equalizing-resistances in the circuits leading to the spring-jack jaws, and springjack wedges controlling said resistances.

5. The combination, with the locals, spring jacks, and connecting-wedges, of a supplemental spring-jack and a switch in one local for disconnecting such local from its source of supply and connectingto the supplemental spring-jack.

6. The combination, with the local circuit normally completed to ground or return through a spring-jack, of a circuit-breaking switch in the connection to the dynamo, a ground-circuit, and a switch-contact whereby said ground may be substituted for the connection to the dynamo.

7. The combination,.with the local circuits normally completed through spring-jacks and equalizing or substitute resistances, of a supplemental spring-jack, an equalizing-resistance normally in the circuit thereof, and a spring-j ack wedge therefor having connection to a branch or loop wire, as and for the purpose described.

8. In a telegraphstation apparatus, the combination, with duplex or quadruplex sending and receiving locals, of springjacks through which said locals are normally completed, and equalizing-resistances placed in the normal spring-j ack circuits and controlled by the spring-jack wedges, for the purpose described.

9. In an electricalswitching apparatus, the combination, with the spring-jack and connecting-wedges, of the supplemental contact b, connected to the main contact through a resistance, as and for the purpose described.

10. In an electrical switching apparatus, the combination, with a series of circuits, each completed through the jaws of a spring-jack, of equalizing-resistances placed in the: connections between the divisions of the subdivided jaw of said spring-jack in each circuit, and connecting-wedges arranged to automatically cut out said resistances on the insertion of the wedges, as and for the purpose described.

Signed at New York, in the county of New York and State of New York, this 6th day of June, A. D. 1889.

MINOR M. DAVIS.

WVitnesses:

WM. H. CAPEL, THos. F. CONREY.

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